The PH of a substance is found by using the PH scale, which measures how acidic or basic substances are. The PH scale determines how strong or weak acids and bases are by measuring the activity of hydrogen ions in certain substances, state experts at UC Davis.
The PH scale works in a logarithmic manner, according to experts at UC Davis. The scale increases by 10, which means that a substance with a PH level of 2 is 10 times more acidic than a substance with a PH level of 3.
The standard PH scale runs from 0 through 14, although substances may exceed the limits on either end. Substances with a PH from 0 to 7 are considered acidic, while those with PH levels from 7 through 14 are basic.